Allow setting Node URL as HTTP Provider (#76)

This'll allow the user to specify any node provider instead of just
using Infura

README.md

@@ -44,7 +44,7 @@ Install the following libraries as dependencies. <br>
     pip  install  python-dotenv
 
 
-To test either of the components, create a `.env` file in the root directory (ebbo) and set variables `ETHERSCAN_KEY` and `INFURA_KEY` as string values from [Etherscan API Key](https://etherscan.io/myapikey) in your profile and Infura once you have an account created one. You will also need a `DUNE_KEY` for running the historical data test. <br>
+To test either of the components, create a `.env` file in the root directory (ebbo) and set variables `ETHERSCAN_KEY` and `INFURA_KEY` as string values from [Etherscan API Key](https://etherscan.io/myapikey) in your profile and Infura once you have an account created one. You can also set `NODE_URL` instead of `INFURA_KEY` if you are using a different RPC provider. You will also need a `DUNE_KEY` for running the historical data test. <br>
 Sample `.env` structure:
 
     INFURA_KEY = 'string key here'

src/apis/web3api.py

@@ -24,8 +24,11 @@ class Web3API:
 
     def __init__(self) -> None:
         load_dotenv()
-        infura_key = getenv("INFURA_KEY")
-        self.url = f"https://mainnet.infura.io/v3/{infura_key}"
+        if getenv("NODE_URL"):
+            self.url = getenv("NODE_URL")
+        else:
+            infura_key = getenv("INFURA_KEY")
+            self.url = f"https://mainnet.infura.io/v3/{infura_key}"
         self.web_3 = Web3(Web3.HTTPProvider(self.url))
         self.contract = self.web_3.eth.contract(
             address=Address(HexBytes(SETTLEMENT_CONTRACT_ADDRESS)), abi=gpv2_settlement